1 RASCAL 4.0 Radiological Assessment System for Consequence Analysis National Radiological Emergency Preparedness Conference March 30, 2010 George Athey, Athey Consulting James (Van) Ramsdell, Pacific Northwest National Laboratory Part 3 - Lou Brandon, Nuclear Regulatory Commission Paul Holland, Exelon Energy RASCAL 4.0

2 Contrast w/RASCAL Highlight new features – new ATD model Case Study - Fixed Parameters Byron NPP, Core uncovered 1 hr 2% release per day, no spray, no filters activity released – 9.5 E5 Curies E5 Curies 4.0 Case Study – Varying Parameters Stability Classes B and E 2 & 8 mph wind speeds, no precip

Byron Unit 2: Source Term 3

Release Pathway 4

Release Pathway Options 5 Minimum 10 m release height is optimum model default

6 Meteorology

Calculate 7 Default 8 hour dose calculation

8 Results New Check this

9 Activity Released 6% lower RASCAL RASCAL 4.0 Notice Cs-137*

10 RASCAL TEDE (top) & CDE Values about 1/3 lower

11 New options Check TEDE

3.0.5 (left) vs 4.0 TEDE 3.9 rem vs 1.2 rem at 2 mi 1.3 rem vs 0.38 at 5 mi 12 8 mph, E Stability

3.0.5 (left) vs 4.0 Thyroid 23 rem vs 5.7 rem at 5 mi 8.9 rem vs 2.4 rem at 10 mi 13 8 mph, E Stability

3.0.5 (left) vs 4.0 TEDE 3.3 rem vs 2.3 rem at 2 mi 1.9 rem vs 0.65 at 5 mi 14 2 mph, E Stability

3.0.5 (left) vs 4.0 Thyroid 36 rem vs 13 at 5 mi 15 rem vs 3.2 at 10 mi 15 2 mph, E Stability

3.0.5 (left) vs 4.0 TEDE 2.1 rem vs 0.44 rem at 2 mi 0.88 rem vs 0.23 at 5 mi 16 2 mph, B Stability

3.0.5 (left) vs 4.0 Thyroid 16 rem vs 3.9 at 5 mi 5.9 rem vs 1.2 at 10 mi 17 2 mph, B Stability

3.0.5 (left) vs 4.0 TEDE 2.4 rem vs 0.33 rem at 2 mi 0.64 rem vs 0.11 at 5 mi 18 8 mph, B Stability

3.0.5 (left) vs 4.0 Thyroid 11 rem vs 1.6 at 5 mi 4.0 rem vs 0.83 at 10 mi 19 8 mph, B Stability

µCi/m 2 at 3.0 miles New Feature Click Cells for Detail 8 mph, B Stability

Radionuclide Deposition 21 Sampling required before decision making

22 30 µCi/m 2 I-131at 3.0 miles Click Cells for Detail Specific Radionuclides

23 Release still in progress but calculation stopped at 8 hr.

24 Monitored Mixtures Can now enter I-131 equivalent release rate

25 Release starts 1:00 AM Duration expected 4 hours Release Pathway – Monitored, Filtered

2 mph, E Stability, Results 26 Check this

27 RASCAL RASCAL 4.0 Both 1000 Ci/s nobles 1 Ci/s I-131 Cesiums corrected, only I-131 & I daughters

28 FM to Dose Enter sample data

Result 29 Deposition time Starts at 4 days Compare to:

30 Radionuclide(µCi/m²) Ba La Cs Cs Cs Ba-137m2.24 I I I Xe-135m3.63 Np Sr Sr Y-91m0.919 Te-131m0.581 Te Te I Compare sample data-slide 79 TF values about 80% RASCAL values Dose unit mrem

Relocation DRLs (mR/h) 31 DRL map contours shrink with decay as days pass

On the Horizon… Automated weather entry Work with DOE – TurboFRMAC consistency Work with DTRA – HPAC consistency Detailed verification and validation State of the Art Reactor Consequence Analysis (SOARCA) source terms Create New Reactor models for RASCAL Continued progress on future model improvements 32

SOARCA Station Blackout Based on MELCOR run at Sandia PWR Scenario – earthquake – no AC power 1 st cladding release - 16 h Containment design leakage increase – 28 h BWR Scenario 1 st fuel cladding release – 10 h iodine release exceeds 1% inventory – 20 h Scenario ready to incorporate into RASCAL 33